To enable desktop audio capture in OBS, configure sndiod(8) with a monitor
sub-device:

    # rcctl set sndiod flags "-s default -m play,mon -s mon"
    # rcctl restart sndiod

Then in OBS, add a "Sndio Input Client" source and set the device to:

    snd/mon

To enable microphone recording, audio recording must be allowed at the
kernel level:

    # sysctl kern.audio.record=1

To persist this setting across reboots, add to /etc/sysctl.conf:

    kern.audio.record=1

For USB microphones, use device snd/1 in OBS.

To enable webcam/camera capture, video recording must be allowed at the
kernel level:

    # sysctl kern.video.record=1

To persist this setting across reboots, add to /etc/sysctl.conf:

    kern.video.record=1
